1. Field of the Invention
This invention relates to computer systems and more specifically to powering up a computer system from a peripheral device connected to a standard parallel port of the computer system.
2. Description of the Prior Art
Personal computers, e.g. portable and desk top computers, often include a power management function. When the computer is inactive (not executing an application program or otherwise in use) the computer is placed in a standby mode. In the standby mode, typically only the memory is powered and a power management logic chip or chips are powered up. When the computer needs to resume operation due to keyboard input or other activity, the power management logic circuitry activates the power supply and powers up other portions of the computer including for instance the CPU (central processing unit).
However this presents the problem that devices such as Multi-Functional Peripherals (such as a combination facsimile machine-printer) connected to a parallel port of the computer may require the attention of the CPU when the CPU is powered down. For instance, if a facsimile is received by the facsimile machine, it must be stored into the computer's disk drive. If the computer is in the standby mode, the facsimile machine-printer connected to the parallel port needs a way to wake up (power up) the CPU of the computer and the disk drive which are powered down in the standby mode. However, no such feature is now available. It is also important that this wake up be performed quickly and be implemented in inexpensive fashion to make it suitable for use with a variety of computers.